Laser Shockwave Technique (LST), which was developed initially for determining adhesion of thin films and coatings to substrates, a high-energy pulsed laser generates a compressive shock wave at the upper surface of a test sample. The compressive shock traverses the sample. After arriving at a predetermined spot of the test sample, the compressive wave is transformed by the free surface into a tensile wave that traverses back through the specimen. A shock wave with amplitude above an interface defined threshold will generate tensile stresses that can de-bond the film/coating from the substrate. By examining the specimen response and using shock wave propagation models, the stress necessary to de-bond the film/coating from the substrate can be determined.
By way of example, LST is one technique for qualifying fuel that characterizes the clad-clad and fuel-clad relationships.
There are drawbacks and deficiencies with existing techniques for shock wave testing, including LST.